Undergraduate Honors Thesis Projects
Date of Award
Spring 4-28-2024
Document Type
Honors Paper
Degree Name
Zoo and Conservation Science-BS
Department
Biology & Earth Science
Advisor
Dr. Sarah Bouchard
First Committee Member
Dr. Sarah Bouchard
Second Committee Member
Dr. Kevin Svitana
Third Committee Member
Dr. Ashley Simons
Keywords
Road salt, Salinization, Gray treefrog, Morphology, Predation response
Subject Categories
Biology | Higher Education | Zoology
Abstract
The extensive use of road salt has increased the salinity of aquatic ecosystems, leading to negative impacts across trophic levels and potential interactions with other biotic stressors. Predation threat can alter tail morphology, slow larval growth, and accelerate metamorphosis in gray treefrogs (Hyla versicolor). The present study aimed to examine the effects of road salt on H. versicolor growth and development and explore potential impacts on plastic predation responses. Larvae were reared in 30 outdoor mesocosms under no-salt-added (110 mg Cl-/L), low (230 mg Cl-/L), and high (1,000 mg Cl-/L) chloride concentrations, with and without a dragonfly larvae (Pachydiplax longipennis) predator. Caged predators were fed five H. versicolor tadpoles daily to induce kairomone production and generate antipredation responses. Salinity and predation facilitated developmental and morphological changes in H. versicolor larvae and induced interactive effects on tail morphology. Salinity induced greater larval growth rates and increases in tail and organ size. Predation did not affect larval growth or any measures of tail morphology, but also increased organ size. While both stressors decreased time to metamorphosis, they produced opposing results, with higher salinity inducing larger froglets and predation inducing smaller froglets. Interactive effects on tail morphology were found, indicating that plastic predation responses were altered at high salt concentrations. This study has important implications for how increases in environmental salinity levels will affect H. versicolor as morphological and developmental changes in larvae can have greater impacts on fitness post-metamorphosis in the terrestrial environment.
Licensing Permission
Copyright, all rights reserved. Fair Use
Recommended Citation
Schmidt, Adilia, "The Effects of Road Salt on Larval Gray Treefrog (Hyla Versicolor) Development and Plastic Responses to Predation Threat" (2024). Undergraduate Honors Thesis Projects. 175.
https://digitalcommons.otterbein.edu/stu_honor/175
Acknowledgement 1
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Acknowledgement 2
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